Black holes in 4d $\mathcal{N}=4$ Super-Yang-Mills
Francesco Benini, Elisa Milan
TL;DR
This work demonstrates that large-$N$ $ ext{N}=4$ SU$(N)$ SYM on $S^3$ houses enough 1/16-BPS states to account for the entropy of rotating AdS$_5$ black holes, by leveraging a Bethe Ansatz formulation of the superconformal index. The authors identify an exponentially large sector in the index at generic complex fugacities that reproduces the Bekenstein-Hawking entropy for Gutowski-Reall black holes via a Legendre transform, while revealing a rich structure of competing exponentials and Stokes lines that signal new physics beyond a single saddle. They also relate the index analysis to $ ext{I}$-extremization and an entropy function framework, and discuss potential instabilities toward hairy or multi-center configurations in certain charge regimes. Overall, the paper provides a nonperturbative CFT count that matches gravitational entropy in AdS$_5$ and uncovers intricate large-$N$ analytic structure with implications for black hole microphysics and holography.
Abstract
We resolve a long-standing question: does the four-dimensional $\mathcal{N}=4$ SU(N) Super-Yang-Mills theory on $S^3$ at large N contain enough states to account for the entropy of rotating electrically-charged BPS black holes in AdS$_5$? Our answer is positive. We reconsider the large N limit of the superconformal index, using the Bethe Ansatz formulation, and find an exponentially large contribution which exactly reproduces the Bekenstein-Hawking entropy of the black holes of Gutowski-Reall. Besides, the large N limit exhibits a complicated structure, with many competing exponential contributions and Stokes lines, hinting at new physics.
